A roundup of oil and natural gas industry news from around the state, nation and world:

Demand for diesel fuel is expected to grow

As gasoline use continues to slip nationwide, demand for the country’s second most popular fuel is headed in the opposite direction.

Gasoline demand has eased over the past several years, spurred both by the recession and increased fuel efficiency. Most forecasts show gasoline demand continuing to steadily track downward over the next couple of decades as new fuel efficiency standards roll out.

But while gasoline use may be falling, demand for diesel continues to grow.Overall energy use by the country’s transportation sector grew by an average of 1.3 percent per year from 1973 to its peak in 2007. From 2012 to 2040, however, demand is expected to decline 4.5 percent, according to the U.S. Energy Information Administration.

The projections show demand to be far from even.

Light-duty vehicles — most of which consume gasoline — are expected to see fuel demand drop 24 percent by 2040, while diesel-consuming heavy-duty vehicles are likely to increase demand by more than 41 percent.

The European Union is pressing the United States to lift its longstanding ban on crude oil exports through a sweeping trade and investment deal, according to a secret document from the negotiations obtained by The Washington Post.

It's not entirely surprising. The EU has made its desire for the right to import U.S. oil known since the U.S. started producing large amounts of it in the mid-2000s. It signaled again at the outset of trade negotiations, and its intentions have become even more clear since.

This time, though, the EU is adding another argument: Instability on its Eastern flank threatens to cut off the supply of oil and natural gas from Russia. "The current crisis in Ukraine confirms the delicate situation faced by the EU with regard to energy dependence," reads the document, which is dated May 27.

The leak comes in advance of another round of discussions on the Transatlantic Trade and Investment Partnership, which kicked off last fall and is expected to encompass $4.7 trillion in trade between the U.S. and the European Union when it's finished (here's an explainer on the deal). That won't happen for several years — if ever — but knowledge of the E.U.'s position has inflamed the already-hot debate over whether to allow the U.S.' newfound bounty of crude oil to be exported overseas.

In a nondescript site in Midland, Texas, an inexpensive new process is cleaning up the extremely salty water that comes up with oil at wells. By the end of next month the technology is expected to be chugging 500,000 gallons per day, furnishing water that’s sufficiently clean to use in hydraulic fracturing for oil and natural gas production.

The technology may provide a way to deal with the increasing amounts of contaminated water the fossil fuel industry is generating as it pursues more and more difficult-to-reach deposits. Many oil formations can produce as much as five barrels of contaminated water for every one barrel of oil. And the volume of this so-called “produced” water is rising as the industry pumps water into nearly depleted wells to enhance oil recovery.

In the Midland plant, the technology is proving more economical than the existing strategy: re-injecting the wastewater back into the wells, while purchasing clean water for use in nearby fracking operations. Right now, gas producers tend to store water that comes back up during the process in man-made ponds and dilute it for reuse. Ultimately they inject the dirty water deep underground for final disposal.

“This is far and away the largest such plant anyone has ever built. Past prototypes have done 200 gallons a day; this is vastly larger, modular, and scalable; if they wanted to double it, they could,” says John Lienhard, a professor of mechanical engineering at MIT who heads MIT’s Center for Clean Water and Clean Energy, where the technology was developed.

OPEC predicted that demand for its crude will decline in 2015 to the lowest in six years as supplies from other producers, led by the U.S., are more than enough to cover the increase in global consumption.

The need for crude from the Organization of Petroleum Exporting Countries will slide to 29.4 million barrels a day next year even as growth in world oil consumption accelerates, the group said in its first assessment of 2015. That’s 300,000 a day less than OPEC’s 12 members pumped in June. It would be the third consecutive annual drop in demand for OPEC crude and the lowest since 2009. The U.S. will provide about two-thirds of next year’s supply growth, OPEC said, amid a shale-oil surge that has made the U.S. the world’s biggest producer.

“Even if next year’s world economic growth turns out to be better than expected and crude oil demand outperforms expectations, OPEC will have sufficient supply to provide to the market,” the group’s Vienna-based secretariat said in the report.

The U.S. has overtaken Saudi Arabia and Russia as the world’s biggest oil producer as it taps shale formations in Texas and North Dakota by splitting apart rocks with high-pressure liquid, a process known as known as hydraulic fracturing, or fracking. Oil prices have remained supported by threats to supplies in OPEC members such as Iraq and Libya, with the Brent benchmark’s loss this year limited to 2.3 percent.

Brent traded at $108.20 a barrel at 10:50 a.m. London time on the ICE Futures Europe exchange.

Global oil demand will expand by 1.2 million barrels a day, or 1.3 percent, to 92.35 million a day in 2015, a faster pace of expansion than this year’s 1.1 million a day, OPEC said.